Unit testing is a valuable skill to have, no matter where your code runs or what it does. It reduces the error rate of your software and can often help force a better structure into your code. In addition, this practice can make it easier to make large changes to your software with less risk, as well as making it easier for new developers to understand the structure of your software.

Numbers are representations of things, not things themselves. We have to be able to store and process numbers in an efficient manner in order for our programs to run well. However, those numbers also have to be accurate. We can’t lose data in the process of storage, retrieval, or arithmetic operations.